1. Technical Field
The technical field relates to a method for preparing a phenolic compound from lignin depolymerization products.
2. Description of the Related Art
Currently, the main source of phenol is crude oil. Crude oil is distillated though an atmospheric tower to form light oil. Light oil is hydrogenated and re-fractionated to form benzene. Benzene is sulfonated, melted and treated by halogenated aromatic alkali to form phenol. Phenol is an important chemical raw material which is capable of making dyes, drugs, phenolic resin and adhesive, etc. Due to limited petrochemical resources, phenol is in short supply every year, for example, there was a shortfall of the global supply of phenol in the amount of 534,000 tonnes in 2011, therefore finding an alternate source of materials and manufacturing technology other than petrochemical phenol is an important task.
The lignin of biomass mainly comprises carbon (C), hydrogen (H) and oxygen (O). Lignin is depolymerized to form phenolic compounds such as 4-methoxyphenol (C7H8O2), o-methoxyphenol (guaiacol, C7H8O2) or 2,6-dimethoxyphenol (syringol, C8H10O3). High-priced phenol (NT$60/kg) or crude phenol (NT$40/kg, a mixture of phenol, methylphenol and dimethylphenol) is acquired in removing the methoxy group of benzene of lignin depolymerization product. Using biomass as a substitute for petrochemical phenol raw materials, which reduces the dependence on petrochemical phenol and helps to enhance the total value of biomass, is a technology with a great source of materials and development potential.